Tyler Cowen asks if we should subsidize or tax research into time travel. Here's my favorite comment, by "dirk":
If time-travel were possible and humans discover how to do it, the odds are greater that it has already been discovered, so to speak, in the future than that we'd discover it in the near-term present, regardless of subsidies. Therefore, the time-travelers are already here if they are going to ever be here. So instead of subsidies we should offer a huge prize for a time-traveler to tell us how it works. Even if some *future* time-traveler isn't in the present now to hear about the prize directly, if we make the prize big enough it will be discovered in the historical record and someone will claim it.
The question then is: what do you get the time-traveler who has everything? Perhaps Obama should hold a press conference and say: "Time-travelers, tell me what you want." Imagine how stupid other countries will feel if that works!
So... what could we use to temp a time traveling?